Caralluma dioscoridis is a low succulent, suckering freely, forming large, dense, colonies up to 1 m across groups (not in cultication). It is a very rare Socotran endemic that shows a unique combination of Caralluma and Orbea / Duvalia / Whitesloanea features. It is believed that the similarity to Caralluma is through convergence and that its true relationships are nearer Orbea prognatha or Duvalia sulcata. In habit (when not in flower) it superficially resembles Caralluma europaca but the affinities (on the basis of stem form only) are significantly vague. The morphology of pollinaria and fruits indicates, as does the name, a relationship of Duvaliandra with Duvalia, while in stem morphology and biogeography, Whitesloanea appears to be much closer. On the other hand, corona, anthers and style head indicate that this Socotran endemic occupies an isolated position. Some authors guess it could be an old wild duvalia-caralluma hybrid.